This invention relates to medical devices and, more particularly, to safety devices to prevent reuse of a hypodermic needle.
Hypodermic needles and syringes have long been used as a quick and easy way to transfer liquids into and out of the body. Indeed, the term “hypodermic” is derived from the Greek words “hypo”, meaning under, and “derma”, meaning skin. Appropriately, fluid (such as a drug or blood) may be drawn up into the barrel of the syringe by inserting a hollow needle associated with the syringe into the fluid, and pulling back a plunger residing within the barrel to create a vacuum. The fluid may be administered subcutaneously, or withdrawn subcutaneously and otherwise dispensed with, by pushing the plunger back into its original position. A user can determine exactly how much material is withdrawn or dispensed by reading the measuring marks on the side of the barrel.
Hypodermic needles are commonly used in medical, veterinary and laboratory fields, and are increasingly accessible to the general public. As a result, needlestick injuries arising from improperly disposed or maliciously discarded needles are a significant risk to professionals and non-professionals alike. Needlestick injuries can introduce into the body harmful materials or micro-organisms from the skin as a result of contaminants on the outside of the needle and/or within the needle bore. Of particular concern is the transmission of blood-borne pathogens, such as the hepatitis B virus (“HBV”), the hepatitis C virus (“HCV”) and the human immunodeficiency virus (“HIV”), which causes Autoimmune Deficiency Syndrome (“AIDS”).
Medical devices incorporating hypodermic needles thus typically include an overcap or other protective device that may be placed over the needle after it has been used. In theory, such a protective device prevents injury arising from later contact with contaminated portions of the needle and sharp needle tip. Although many design variations exist, however, protective devices are often difficult to manipulate, and the practice of affixing the overcap or other protective device over a used needle may itself render one susceptible to an accidental needlestick. In fact, the majority of accidental needlestickes occur when needles are being re-capped. Moreover, such overcaps or devices may be unreliable due to difficulty in distinguishing a hypodermic needle that has been properly secured from one that has not.
In view of the foregoing, what are needed are apparatus and methods to secure a hypodermic needle that are simple to use and manufacture, and provide reliable protection against needlestick injuries. Further what are needed are apparatus and methods that clearly indicate whether a hypodermic needle has been properly secured and is, therefore, safe to handle. Such apparatus and methods are disclosed and claimed herein.